1. Field of the Invention
The present invention relates to magnets and more particularly to therapeutic flexible magnetic sheets.
2. Description of Related Art
Flexible magnetic sheets have been disclosed for various uses. One of the primary uses of such devices is for therapeutic use on humans such as for suppressing nerve cell action and increasing blood flow to reduce pain. There are numerous devices that have attempted to maximize the effect of such therapeutic use of magnets.
There are several design factors that determine the degree of effectiveness of a multi-polar therapeutic magnetic device. A consideration in the design of such devices is known as the Hall effect. It is desirable that a multi-polar magnetic field intersect the blood vessels at as close to an angle of ninety degrees as possible. The magnitude of the therapeutic effect may decrease proportionally with the degree of deviation from ninety degrees. For example, a magnetic field running parallel to a blood vessel may have no therapeutic effect.
Examples of approaches that attempt to achieve a maximum therapeutic effect are as follows. Magnetic belts are known that have a pattern of discrete permanent magnet discs received in circular holes arranged in a rectangular pattern in a substrate, such as a flexible magnetic material, for imparting a magnetic flux normal to the material in the lumbar region to reduce stiffness or pain.
Other approaches include a magnetic plaster formed of an elastic magnetizable plastic sheet material, magnetized in a series of parallel stripes of alternating polarity, at a spacing of 4-10 mm. This arrangement is a basic parallel line multi-polar pattern that is designed to enable positioning of the sheet on the patient""s skin with the stripes oriented transversely to the patient""s vasculature so that blood flow traverses the alternating poles. However, there are several possible orientations in which the vasculature will be unaffected by the magnetic field.
It is also known to use a magnetic sheet which arranges the magnetic poles in a pattern which is concentric, angular or radial about a common axis or center. These arrangements are intended to permit the patient to position the sheet in any orientation on the skin and still have the pattern traverse the underlying vasculature. However, these arrangements have several limitations.
The patterns of such arrangements cannot be expanded indefinitely in size to cover large areas of a patient""s body. As the pattern is scaled to larger sizes, the circumferential extent of each area of one polarity increases to the point where it is no longer effective to induce any changes in magnetic flux. For example, in the concentric case, each ring becomes very large at a distance spaced from the center; so large that an underlying blood vessel oriented tangentially to the pattern can travel a substantial distance without crossing a magnetic polarity boundary. The same situation can result in the angular or radial pattern. Additionally, as the angular or radial pattern is enlarged, the lengths of segments increase so that a blood vessel, aligned lengthwise to the segment, does not necessarily cross areas of alternating polarity. Moreover, if the blood vessel does not traverse the apparatus directly through the center, there is no possibility of achieving a ninety degree intersection with a polarity boundary line.
Other approaches attempt to improve upon the arrangements discussed above by providing curved first and second areas of alternating magnetic polarity. However, there is still a possibility that a blood vessel could have no intersection when it is oriented at a forty-five degree angle that does not pass through a north pole circle of the magnet.
Accordingly, there is a need in the art for an improved therapeutic flexible magnetic sheet.
A therapeutic device is provided. In an embodiment of the present invention, the therapeutic device includes a sheet having a plurality of magnetized areas defined by a grid. The grid includes a plurality of straight lines and a plurality of curved lines where the plurality of straight lines intersect the plurality of curved lines.